System and method for performing flood zone certifications

ABSTRACT

After FEMA flood maps are scanned and converted to raster maps on a computer system, they are georeferenced. The georeferenced raster maps are stored on the system. Map inset polygons are surrounded by a virtual bounding box and a determination is made whether each grid rectangle intersects any bounding box. For each such intersection, the relevant inset polygon is traced to determine if it actually intersects the grid rectangle. If there is such intersection, the inset polygon is added to a list attached to the grid rectangle. At the end of the process, the list for each grid rectangle identifies each inset polygon intersected thereby. When an address of a property subject to a flood zone determination is entered into the system and geocoded, the grid rectangle containing the address is immediately called up. If only one inset polygon is on the list, it is used to make the flood determination. If more than one inset polygon is on the list, the various polygons are examined to determine which one is appropriate for making the flood determination, which is then made.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part (“CIP”) of and claimspriority based on pending U.S. Patent Application entitled “System andMethod for Performing Flood zone Certifications,” Ser. No. 09/537,161,filed Mar. 29, 2000. Furthermore, this application shares specificationand figures with commonly assigned, copending U.S. Patent Applicationsentitled “System and Method for Georeferencing Digital Raster Maps,”Ser. No. 09/537,849, filed Mar. 29, 2000; “System and Method forGeoreferencing Maps,” a continuation-in-part of the '849 application,Ser. No. ______, filed ______; “System and Method for SynchronizingRaster and Vector Map Images,” Ser. No. 09/537,162, filed Mar. 29, 2000;and “System and Method for Synchronizing Raster and Vector Map Images,”a continuation-in-part of the '162 application, Ser. No. ______, filed______; all of the foregoing being incorporated hereinto by reference.

FIELD OF THE INVENTION

[0002] The present invention generally relates to the analysis ofgeographic features and characteristics, and, in particular, to a systemand method for performing flood zone determinations.

BACKGROUND OF THE INVENTION

[0003] FEMA Flood Maps

[0004] The Federal Emergency Management Agency (FEMA) publishes a largeset of “flood maps.” These paper maps are the official, Federallysanctioned source for determining flood risk. The flood maps delineateregions that are assigned a flood zone designation from among a limitedset of possible designations.

[0005] For example, a region designated “Zone A” on a flood map is ahigh risk area, which FEMA believes has at least a 1 in 30 chance offlooding during any given year. A region designated “Zone V” combinesthe properties of a “Zone A” with the additional risk of wave action orflowing water. Other zone designations include “X,” “AE,” “B,” “C,” and“D,” see FIG. 2. In the foregoing context, performing a “flood zonedetermination” (also known as a “flood hazard determination” or a “floodcertification”) relative to a location entails a two-step process: (1)determining, based on FEMA flood maps and other materials, theFEMA-designated flood zone for the location in question, and, then, (2)completing required paperwork to report this determination (along withcertain other required information) to interested parties, such as homebuyers, their lenders, and real estate brokers.

[0006] FEMA flood maps come in a variety of styles, but broadly speakingthey can be divided into two types of maps, namely, index panels orindex panel maps, see FIG. 5, and regular panels or regular panel maps,see FIGS. 1-4 and 7.

[0007] Referring to FIG. 1, a regular panel map 10 shows a relativelysmall geographic area at a fairly high level of detail. Each regularpanel 10 depicts various “features” of the relevant area. These featuresinclude (without limitation) streets 12 railroad tracks 14, streambeds16, lakes, intersections 18 of the foregoing, and detailed delineationsof the boundaries of various extant flood zones 22(see FIG. 2) and theirclassifications.

[0008]FIG. 2 depicts a regular panel map 10 in which flood zones 22 aredepicted. As is typical, the flood zones 22 are denoted or “flagged” asvariously shaded regions contained within irregular curvilinearboundaries (the “flood zone boundary”). Legends or labels 30 on regularpanels 10 designate the types of flood zones 22 that have been shaded.With the exception of regular panels 10 described as “not printed”(“PNP”) and panels presenting flood zone-designated communities,described in greater detail below, all flood zone determinations aremade by reference to appropriate regular panel maps 10.

[0009] Continuing to refer to FIGS. 1 and 2, each regular panel map 10is bounded by a “neatline,” that is, a rectangular frame or border 32surrounding the geographic area 33 of interest. The geographic area ofinterest 33 may not completely “fill” the neatline 32, as indicated at34 in FIGS. 1 and 2. For example, the actual geographic area 33contained within the neatline 32 of a regular panel 10 might consist of(a) a portion 35 of a community and the designated flood classificationof the portion and (b) unincorporated or other portions 36 whichsurround, are surrounded by, or abut the community, and which have noflood classification depicted on the panel 10.

[0010] Referring to FIG. 3, if FEMA has designated a regular panel map10 as being applicable to determining the flood zone classification ofonly a portion 35 of an incorporated community, then the regular panel10 cannot be used to determine the flood classification of any depictedunincorporated areas 38. According to FEMA protocol, the foregoingobtains whether or not flood zones for the unincorporated area are shownon the regular panel 10. Indeed, a FEMA panel map 10 often does not showflood zones for areas outside of the designated region for the map 10(the designated region 35 is a portion of the community in thisexample). Sometimes the area outside of the designated area is justshown as a blank area on the panel, as at 38. Regardless of how much orhow little detail is shown, by convention, a flood determination can bemade using a panel 10 only in the region designated by FEMA.

[0011] The “inset” 44 of a panel 10 is any geographic region that isboth shown on the panel 10 and as to which FEMA mandates the applicationof the flood zone designations set forth on the panel 10. A panel inset44 may be self-connected (connected with all parts of itself) as inFIGS. 1-3, or, as shown in FIG. 4, it may comprise two or moreself-connected regions 46,48 separated by one or more intervening,non-designated areas 50 on the panel 10 and may include othernon-designated areas, such as those shown at 52 and 54. The insets 44 ofa panel map 10 may comprise a collection of disjoint, self-connectedregions 46,48 which collectively contain all of the designated area ofthe panel 10, and themselves constitute a subset of the geographicregion contained within the neatlines 32.

[0012] Thus, from the foregoing, an actual map panel 10 consists, ingeneral, of three parts: (1) the inset(s) 44, (2) other (non-designated)geographic regions 34,36,38,50,52,54 within the neatlines 32, which arenot included within the inset(s) 44, and (3) areas of the panel whichare outside of the neatlines 32, and generally show various types oftextual information such as a map legend, the map panel number, andpanel effective date, etc. It is true that, in the ideal case, an inset44 should include only designated regions of the panel 10, but as apractical matter it is sometimes convenient to include somenon-designated areas within the insets, so as to simplify the process ofgathering inset border data.

[0013] Referring to FIG. 5, an index panel map 60 shows a considerablybroader area than a regular panel 10, but at a lesser degree of detail,and usually without the flood zones being indicated thereon. Typically,an index panel 60 shows a broad geographic view of the locations of thevarious regular panels 10 that make up an entire community, or otherlarge geographic area. It should be noted that, while FEMA “defines”communities, these FEMA-defined communities often do not correspond toone's intuitive sense of what a community is.

[0014] The index panel 60, generally depicted in FIG. 5, provides itsbroader, less detailed overview by displaying an “outline” of regularpanels 10, that is, the neatline boundaries 32 of each of its regularpanels 10 against a background of major geographic features (e.g.municipal boundaries, highways, lakes, etc.). The outlines of theregular panels 10 bear legends or labels informing of the correspondingdesignation of its regular map panel 10, as represented by “XX,” “YY”and “ZZ” in FIG. 4. The designations “XX,” etc. are set forth on thepanels 10 outside the neatlines 32. Index maps 60, in effect, show howto “put together” the panel map 10 “jigsaw”, that is, how to associatepanel maps 10 with each other to form a grid thereof, grid lines 62thereof being comprised of the aligned and/or overlapping neatlines 32of adjacent panels 10.

[0015] Until the advent of the present invention, the primary purpose ofthe index maps 60 has been their use as an aid in manually determiningwhich of the panel maps 10 should be consulted in order to make a floodzone determination. For example, if a property is known to be located inCommunity A, then a map analyst might first locate the property on theCommunity A index map 60. The analyst could immediately determine - - -by examining the neatline borders 32,62 and the labels “XX,” “YY,” “ZZ”displayed on the index map 60 - - - which regular panel map 10 toconsult. Since there are hundreds of panel maps 10 in the index map 60of various communities, identification of a particular panel map 10 byexamining an index map 60 can be effected more quickly than seriallyexamining large numbers of panel maps 10. The present invention providesother, much more efficient ways of determining the correct regular panelmap 10 applicable to a particular location.

[0016] Index maps 60 also contain neatline borders 32 for panel maps 10that are not printed as such, and which are designated “panel notprinted” or “PNP.” As this name suggests, no actual panel map 10 is everprinted for a PNP. Instead, the relevant index map 60 displays the floodzone classification for the region contained within the PNP neatlineborders 32. Accordingly, In the case of a PNP, the flood zoneclassification is determined from the index map 60, rather than from aregular panel 10.

[0017] In addition to the foregoing techniques, flood zonedeterminations can also be made on the basis of FEMA's denoting certaincommunities as “flood zone designated communities.” In this event, FEMAmandates that a denoted community have the same flood zoneclassification throughout. As a consequence FEMA does not publish anyflood panels - - - either regular 10 or index 60 - - - for thecommunity. A property located anywhere in that community assumes theflood zone classification of the community.

[0018] Digital Raster Maps

[0019] A digital raster map image may be thought of as a number ofpoints selectively present at each X,Y coordinate of a Cartesiandisplay. These points are usually called “pixels.” Besides having anaddress at an X,Y location, a pixel may have a “value,” usually anumeric quantity designating a specified color or grey-scale value forthe pixel. The X,Y location and value of each pixel is data that may bestored. A digital raster map may be created by optically, digitallyscanning a conventional paper map and thereafter using a computer systemto define and/or display it in terms of its pixel locations and colorvalues. Commonly used formats for storing scanned images currentlyinclude TIFF, JPEG, and PNG. Any FEMA regular panel 10 or index panel 60may be represented as a digital raster map.

[0020] Digital Vector Maps

[0021] A vector map may be viewed as a “virtual” map that comprises, ineffect, a collection of stored data. The stored data define thelocations of plural nodes and plural straight-line segmentsinterconnecting the nodes. The stored data defining a vector maprepresents geographic information in the form of collections ofpoints - - - the nodes - - - and line segments interconnecting the nodesto form polygons, i.e., closed figures comprised of line-interconnectednodes. These points, lines, and polygons may have additional informationassociated with them. For example, the stored data may indicate that aparticular point or node is the location of the capitol building, orthat a selected polygon describes the border of Lake Placid. Thepolygons are surrogates for, or representations of, the actualcurvilinear configuration of various geographic features: streets,streams, lakes, cities, counties, etc. Typically, the features - - -nodes alone or two or more interconnected nodes - - - are presented interms of latitude/longitude (or lat/lon) values. If this or anotherearth-referenced system is used to locate the nodes of the map, the mapis said to be georeferenced. A visually sensible map may be “drawn” fromthe stored data

[0022] In view of the fact that georeferencing of digital raster mapimages plays a key role in the present invention, the precise meaning ofthis term, for the purposes hereof and as used herein, is set forthbelow.

[0023] Georeferencing

[0024] A raster map image is said to be “georeferenced” if there existmathematical functions, f and g, such that one function can be used toconvert the X,Y coordinates of the pixels describing the map image tocorresponding latitude/longitude coordinates and the other function canbe used to convert the latitude/longitude coordinates of the pixels ofthe image to their corresponding X,Y coordinates. In other words, f andg effect the following:

[0025] 1. If (x, y) represents a pixel location on a digital raster mapimage, then f(x, y)=(Lon, Lat) represents the longitude and latitude ofthe corresponding physical location; and

[0026] 2. If (Lon, Lat) represents a physical location that lies withinthe region covered by the map, then g(Lon, Lat)=(x, y) represents thepoint on the digital raster map image that corresponds to that longitudeand latitude.

[0027] In the previous paragraph, (x,y) defines a point pursuant to thenatural internal coordinate system of the raster map image. Most digitalvector map images use longitude and latitude as their internalcoordinate system. Accordingly, most digital vector maps can beconsidered to be trivially georeferenced per se. Most digital raster mapimages use the pixels of its image as a kind of natural coordinatematrix. Such a raster map image is not inherently triviallygeoreferenced and requires the operation of a non-trivial georeferencingfunction to convert back and forth between coordinate systems.

[0028] Most FEMA maps do not contain any latitude/longitude informationthat would be useful in georeferencing their scanned raster image. Somerecently FEMA-issued panels do show latitude/longitude values at certainpoints thereon, but such panels are in a distinct minority whenconsidered in the context of the 100,000+ panels that FEMA currentlyprovides.

[0029] Before real property is bought, sold, or insured, it is commonpractice to examine the property for the risk of flooding. This iscommonly done by examining a map depicting the flood zone in which theproperty is located. The Federal Emergency Management Agency (FEMA)assigns flood zone classifications and publishes a library of ten ofthousands of paper maps showing the various flood zones and theirlocations in the United States. A determination of whether a propertyresides in a flood zone and, if so, the classification of such floodzone has, until the advent of the present invention, been typicallyperformed in the following manner.

[0030] First, the address of a selected parcel of real property isexamined, and the location of the property is determined as aconsequence thereof. This may be achieved, for example, through the useof a geocoding system, or by examining an available street map. Next, amap analyst attempts to determine which one(s) of the many thousands ofFEMA flood maps contain or depict the location of the property. Thisdetermination may entail false starts, dead ends and misdirection andmay occasionally require hours of effort before the identity of theflood map containing the property is found. During this process the mapanalyst may retrieve, from map storage, and view numerous paper mapsbefore determining the one containing the property's location.

[0031] Third, having retrieved the required paper map, the map analystnext determines where the property is located on the FEMA map. Finally,the map analyst examines flood zone notations on the map at theproperty's location in order to determine its flood zone status.

[0032] This foregoing manual process can be somewhat improved byscanning the paper FEMA maps into a computer to produce stored digitalraster maps, which can be retrieved and viewed as necessary. A digitalraster map is a map image that resembles a conventional paper map inthat it presents an image of the mapped area, but has no additionalunderlying data associated with the features of the map. A raster map istypically created by scanning a conventional paper map, and is agrid-based map composed of pixels (or dots) of color or black and white.Each pixel in the grid can be referenced by Cartesian X,Y pixelcoordinates, and has an associated value indicating the color of thepixel. Raster images are commonly referred to as “bit mapped” images.

[0033] A vector map comprises polygons - - - nodes connected togetherwith straight line segments - - - rather than pixels, to describe animage. Unlike a raster map, in which the map image is simply stored anddisplayed as a grid of pixels each having an X,Y coordinate, a vectormap is drawn from a set of underlying data stored, for example, in acomputer memory. A vector map is created through the placement of thenodes on a plane and the connection together of those nodes withstraight-line segments. The nodes and lines may be attributed withstored tables of data such as elevations, values, names or otherinformation relative. Vector data can be displayed in three dimensionsif the lines are attributed with z values, modified or changed relativeto user need, or layered to allow for turning off and on the viewing ofdifferent information.

[0034] Because of their feature attribution properties, vector maps areparticularly useful for displaying geographic data on a computer system.Vector maps are used to display boundaries or lines that denote theposition and extent of features, such as county boundaries or linesdenoting stream and river systems. It is also very easy to view ormanipulate the data underlying a vector map, for example to view orchange the elevation of a feature.

[0035] Also, because vector maps are drawn from stored data whichdescribe the locations of features shown, they are often inherentlygeoreferenced. Georeferencing is the process of relating sourcecoordinates to referenced geographic coordinates, which are typically instandard latitude/longitude. An image or a vector file is georeferencedto be used within a mapping/geographic environment. In a vector map, thedata from which the map is drawn will typically already include ageographic coordinate set.

[0036] Modern GIS systems normally make use of digital vector based mapinformation. However, a vast legacy of paper based map informationexists. It is very expensive and time consuming to convert all of theinformation on these paper maps to a digital vector format. In manycases the scope and expense of such conversions render them completelyimpractical. However, even when a complete conversion to digitalvector-based format is not feasible, it is still possible to obtain someof the benefits of computerized map systems by converting the paper mapsto digital raster maps (by scanning them), followed by georeferencingthe raster images. After georeferencing, there is a clear relationshipbetween the X,Y coordinates of each pixel in the raster map, and thegeographic - - -latitude,longitude - - - coordinates of each pixel.

[0037] Since flood zone determinations are typically performed usingpaper FEMA maps, it would be desirable to provide a system and methodfor performing flood zone certifications that is faster and can beperformed less expensively than the process described above.

SUMMARY OF THE INVENTION

[0038] It is, therefore one object of the present invention to providean improved system and method for analyzing geographic traits andcharacteristics. It is another object of the present invention toprovide an improved system and method for performing flood zonedeterminations. However, it should be understood that the presentinvention relates to analyzing any geographic, ecological,climatological or other trait that is described or indicated on ageographic map, as by shading, coloring or otherwise highlightingvarious portions of the map to indicate the presence, absence ormagnitude of the trait.

[0039] The foregoing objects are achieved in the following generalmanner. The present invention provides a system and method forperforming flood zone determinations or assessments of other traits ofselected geographic areas using scanned, digital raster map images oforiginally non-georeferenced maps - - - in the case of flood zonedeterminations, these are FEMA paper maps that have been georeferenced.Such georeferencing is preferably effected according to the invention ofthe above-noted commonly assigned '849 application and the CIPapplication based thereon, but any method that imparts latitude andlongitude coordinates to the pixels of the raster map may be used.

[0040] To determine the flood zone classification or to assess anothertrait of a particular property, a user first enters the street addressor full legal address of the property into a data processing system. Thesystem determines from the address, possibly with user intervention, thelatitude and longitude of the property location. The system thendetermines which georeferenced raster map or maps include or may includethat address and the particular property designated thereby.Specifically, if the system identifies a single georeferenced raster mapas the only map on which the address appears, that georeferenced rastermap is retrieved and utilized to generate a flood zone certificate forthe property. If, as is possible, the system identifies two or moregeoreferenced raster maps as containing, or as likely to contain, theaddress, a “short list” of possible georeferenced raster maps isultimately produced. It is then determined which of severalgeoreferenced raster maps on the short list contains the property. Afterthere is identified the one georeferenced raster map that both containsthe property and is properly usable to determine flood zoneclassifications for the property, the user examines the flood zone orother data thereon. Alternatively, the system can compare the geographiccoordinates of the property against a database of flood zone boundariesfor an automated flood zone determination. The system can also generate,store, and produce flood zone certificates according to the flood zonedetermination.

[0041] More specifically, the present invention relies on theavailability of a complete set of scanned and georeferenced images ofall extant FEMA maps in raster format and the storage of the FEMA mapsand the respective georeferencing functions correlating their pixels'coordinates to the lat/lon coordinate system of a stored vector map.Georeferencing FEMA paper maps is covered in commonly assigned,copending '849 application and in the CIP based thereon. Preferably, theuser also has the ability to synchronize the display of the FEMA mapwith any other georeferenced map, such as the vector map, as set forthin the commonly assigned, copending '162 application and in the CIPbased thereon. The '849 application and its related CIP applicationprovide for the generation and fine tuning of a georeferencing functionwhich mathematically relates each pixel of an ungeoreferenced rastermap, showing flood zone classifications, to the latitude,longitudecoordinates of its corresponding geographic location.

BRIEF DESCRIPTION OF THE DRAWINGS

[0042]FIGS. 1, 3, 4 and 7 are stylized representations of initiallynon-georeferenced FEMA raster panel maps;

[0043]FIG. 2 is a reproduction of an initially non-georeferenced FEMAraster panel map;

[0044]FIG. 5 is a stylized depiction of a FEMA index map;

[0045]FIG. 6 is a reproduction of a portion of a vector map showing thesame geographic area as FIG. 2;

[0046]FIG. 8 is a flow chart of a process in accordance with a preferredembodiment of the present invention; and

[0047]FIG. 9 is a generalized view of a computer system for effectingthe present invention.

DETAILED DESCRIPTION

[0048] The present invention provides, inter alia, for determining theflood zone classification of specific real property as describedhereafter.

[0049] Before the system is used to determine the flood zoneclassification of a particular property - - - or to assess some othertrait present at or associated with the property - - - a virtual grid ofrectangular regions is defined. The virtual grid covers a geographicregion that contains all of the geographic area contained on the FEMAmaps or other maps conveying information related to geographic areas.Each of these gridrectangles is defined to be the set of all locationswith latitude between specified lower and upper bounds, and longitudebetween specified lower and upper bounds. For example, onegrid-rectangle might be the set of all (latitude, longitude) satisfying35.1<=latitude<35.2 and 93.5<=longitude<93.6. For each grid-rectanglewhose area intersects the area covered by some inset on a FEMA or othertrait-indicating map, a list of all such intersecting insets is created.

[0050] It should be recognized that initially “attaching to” orassociating with first each grid rectangle a list of all the insets withwhich it intersects substantially shortens the time it takes to searchfor the inset containing the property of interest. Specifically, becauseof the simple nature of the virtual first grid system, it is quite easyto calculate which grid rectangle contains a specified property. And, ifthe first grid rectangle containing the property has attached thereto alist of the insets which intersect the grid rectangle, a fortiori, ifthe property intersects a flood map inset, that inset is one of theinsets contained on the list attached to the first grid rectangle. Ineffect, then, the insets on the grid rectangle's list constitute a “longlist” that is a list of all insets that possibly contain the property.The long list is quite limited, compared to the total number of insetsderived from FEMAor other maps, and selecting a “short list” or “the”inset becomes quite expedient.

[0051] Referring to FIG. 7, the procedures for achieving the foregoingare set forth.

[0052] A “bounding box” 70 is calculated or constructed for each insetpolygon 72 generated during the georeferencing procedures of the '849application. As used herein, a bounding box 70 is the set of geographiclocations, (latitude, longitude), defined by {Minimum latitude of inset72}<=latitude<{Maximum latitude of inset 72} and {Minimum longitude ofinset 72}<=longitude<{Maximum longitude of inset 72}. Put another way,it is the smallest imaginary or virtual rectilinear quadrilateral thatcan be drawn or constructed to just contain an irregular polygon 72 withthe sides of the quadrilateral having either a North-South or East-Westorientation.

[0053] Using the bounding box 70 as a “polygon,” a determination is madeof all first grid-rectangles 74 that are overlapped or intersectedthereby. Each overlap or intersection, indicated by large dots in FIG.7, denotes a grid rectangle 74 that might overlap, or be overlapped by,an inset polygon 72. (Note that in FIG. 7 the inset 44 does not actuallyintersect some of the dotted grid rectangles 74.)

[0054] A second virtual grid is defined, the members of which are thosefirst grid rectangles 74 that are intersected by the bounding box 70and, therefore, might be intersected by the bounding box's inset 44.Initially mark or denote these grid rectangles 74 initially in thesecond grid as “not processed.”

[0055] As shown by the arrow 76 in FIG. 7, serially traverse the borderor boundary of the inset polygon 72 - - - the nodes or vertices 78 andstraight line segments 80. (The inset polygon 72 was generated when theFEMA maps 10 and 60 were georeferenced, as set forth in the '849application and the CIP application based thereon.) As each line segment80 of the inset polygon 72 is traversed, it is determined which gridrectangles 74 of the second grid are intersected by the segment 80. Ifboth endpoints 78 of the segment 80 lie within a single grid-rectangle74 this determination is straightforward. If the endpoints 78 lie withindifferent grid-rectangles 74, then the set of all intersecting gridrectangles 74 can be determined by examining the points where thesegment 80 crosses grid rectangle borders. Each border crossingrepresents a traversal path from one second grid rectangle 74 into anadjacent second grid rectangle 74.

[0056] If, during traversal of the inset polygon 72, one or more of thesegments 80 is found to intersect a particular second grid rectangle 74,then there is intersection between the second grid rectangle 74 and theinset polygon 72. If no such intersecting segment 80 is found, theneither the second grid rectangle 74 is surrounded by and entirely withinthe inset polygon 72 - - - there is intersection - - - or the secondgrid rectangle 74 is wholly outside the inset polygon 72, and there isno intersection.

[0057] If, during traversal of the inset polygon 72, one or more of thesegments 80 is found to intersect a particular second grid rectangle 74,then the inset 72 is added to the list of insets 72 that intersect thatsecond grid rectangle 74 (if it is not already on that list). Any suchgrid rectangle 74 is now denoted as “border” and “processed.”

[0058] For each second grid rectangle 74 that remains “not processed”proceed as follows:

[0059] (i) Calculate the center point of the grid rectangle 74;

[0060] (ii) Use a point-in-polygon algorithm to determine if the centerpoint is contained within the inset polygon 72;

[0061] (iii) If the center point is contained within the inset polygon72, then the entire grid rectangle 74 must be contained within the insetpolygon 72. The inset 44 is added to the list for the grid rectangle 74,and the grid rectangle 74 is marked “inside” (but still “notprocessed.”) Now iteratively apply the rule that any “not processed”grid-rectangle 74 that is adjacent to a grid-rectangle 74 marked“inside”, must also be entirely inside the inset polygon 72, and shouldtherefore also be denoted as “inside.” When this rule has been appliedto all neighbors of a particular “not processed,” “inside”grid-rectangle, then it should be marked as “processed;”

[0062] (iv) If the center point is not contained within the inset 44, asdetermined by a point-in-polygon procedure, the entire second gridrectangle 74 must be wholly outside the inset. The inset 44 is not addedto the grid rectangle's list and the grid rectangle 74 is marked“outside,” (but still “not processed.”) Now iteratively apply the rulethat any “not processed” grid-rectangle 74 that is adjacent to agrid-rectangle 74 marked “outside”, must also be entirely outside theinset polygon 72, and should therefore also be denoted as “outside.”When this rule has been applied to all neighbors of a particular “notprocessed,” “outside” grid-rectangle 74, then it should be marked as“processed.”

[0063] (v) Repeat the procedure for remaining “not processed”grid-rectangles.

[0064] Thus, the system and method of the present invention begin withthe georeferencing method and system of the '849 application and the CIPapplication based thereon and perform an initial step of creating a listfor each rectangle grid. Each list contains and identifies all FEMAinsets that intersect the list's grid rectangle 74. The location of realproperty, expressed in latitude, longitude can be associated with thegrid rectangle that contains it, which, in turn associates it with ashort list of all possible insets that could contain the property.Various methods may be used to quickly examine the short list anddetermine which inset is the flood control map applicable to theproperty.

[0065] When a customer submits the location of the property on which aflood - - - or other - - - determination is to be made, the submissionmay take several forms. Often the location is given by providing theproperty's street address. Sometimes a legal address is given, which maycontain a “metes and bounds” description; sometimes the customerprovides the latitude and longitude coordinates of the property. Thecustomer request for a flood determination and the accompanying locationinformation forms the basis for creating a work order which is stored onthe computer system.

[0066] From a work order, the latitude,longitude coordinates (“lat/lon”)of the property must be determined. As noted above, the customer maysometimes provide this information directly, thus eliminating the needfor further effort. Generally, however, the address (street, legal, orother) must be converted into lat/lon. This conversion is called“geocoding.” Once geocoding has been performed - - - the lat/loncoordinates have been determined - - - the lat/lon are recorded on thecomputer system along with other work order data. Common methods forgeocoding, include, but are not limited to:

[0067] (a) Automatic methods, including

[0068] (i) Commercial “scrubbing and geocoding” software, which usuallyreturns the lat/lon coordinates of a street address.

[0069] (ii) A database of locations specified by legal address.

[0070] (b) Methods requiring human intervention

[0071] (i) A paper map, plat map, web site, telephone call to aresponsible agency, or other means is used to locate the property, basedon whatever location information is provided. Thereafter, the property'slocation is designated on a georeferenced map, which through itsgeoreferencing implies the appropriate lat/lon coordinates.

[0072] (ii) In one embodiment of the present invention, the person“clicks” the mouse cursor on the property's location as displayed on adigital vector street map image licensed from a commercial source.

[0073] There must be selected the appropriate FEMA flood map image fromwhich the flood zone classification of the property can be made. Morespecifically, the system determines which inset 72 on which flood mapimage 10 - - - both of which have been georeferenced, preferably by themethod of the '849 application and the resulting CIP application - - -should be used to make the flood determination for the property. Thereare a very large number of insets contained in 100,000+ FEMA flood maps.Accordingly, the final choice of the proper inset is made in two stages.The first stage (a) is automatically accomplished by the computersystem, while the second stage (b) may require human intervention.

[0074] (a) Automatically create a “long list” of possible insets whichmay include the property. This process is described above, and involvesthe explication of the virtual first grid of rectangles, expressed inlat/lon coordinates, which covers a geographic region that contains allflood map image insets. In specific implementations of the presentinvention, the grid has 20,000 lines in the North-South direction, and40,000 lines in the East-West direction and covers the entire globe,which results in grid-rectangles of approximately 1 kilometer square atthe equator (and smaller elsewhere). Due to the simple nature of thisfirst grid structure, it is a simple matter to calculate which firstgrid rectangle contains any given point. It is also simple to determinewhich grid rectangles contain any part of a given great curve connectingtwo points of given latitude and longitude.

[0075] Geocoding the address of the property, permits the determinationof the selected first grid-rectangle that contains the property.Selection of the first grid-rectangle permits access to its long list ofintersecting insets. If the property is located on any inset, then itmust be one of the insets in this list.

[0076] (b) Point-in-polygon testing of the property with respect to eachpolygon in the long list is performed to determine which panel mapinsets 44 contain the property. This list of insets in called the “shortlist.” The borders of each inset in the short list are displayed on thesystem. This display and associated information on the insets are usedby the user to determine which is the single inset 44 (and thereforepanel 10) from which the property's flood zone classification may bedetermined. The user determines the flood zone classification of theproperty from the appropriate panel map. The user will also note thespecific community and/or county containing the property, when more thanone possibility exists. Additional related information—community status,panel effective date, insurance availability, community number, lenderID number, and useful property-locating data can be determined using adatabase of flood information. Note that a purely automated system forcompleting Flood Hazard Determinations (no human intervention) can firstbe tried, and the job need only be passed to this system in the event ofthe failure of the purely automated system

[0077] With reference to FIG. 9, a block diagram of a data processingsystem in which the present invention may be implemented is depicted.Data processing system 100 includes processor 102 and associated L2Cache 104, which in the exemplary embodiment is connected in turn to asystem bus 106. System memory 108 is connected to system bus 106, andmay be read from and written to by processor 102.

[0078] Also connected to system bus 106 is I/0 bus bridge 110. In theexemplary embodiment, data processing system 100 includes graphicsadapter 118 connected to bus 106, receiving user interface informationfor display 120. Peripheral devices such as nonvolatile storage 114,which may be a hard disk drive, and keyboard/pointing device 116, whichmay include a conventional mouse, a trackball, or the like, areconnected to 1/0 bus 112.

[0079] The exemplary embodiment shown in FIG. 9 is provided solely forthe purposes of explaining the invention and those skilled in the artwill recognize that numerous variations are possible, both in form andfunction. For instance, data processing system 100 might also include acompact disk read-only memory (CD-ROM) or digital video disk (DVD)drive, a sound card and audio speakers, and numerous other optionalcomponents. All such variations are believed to be within the spirit andscope of the present invention. Data processing system 100 is providedsolely as an example for the purposes of explanation and is not intendedto imply architectural limitations.

[0080] The data processing system described above can also include oneor more image scanners, to convert a map from paper format to a digitalraster map.

[0081] The preferred embodiment provides a system and method forperforming flood zone determinations using scanned, georeferenced,digital raster map images. The user, to determine the flood zoneclassification of a particular property, first enters the streetaddress, or full legal address, into a data processing system. Thesystem determines, from the address, which raster map includes thatparticular property. The system retrieves that map, and utilizesgeoreferencing information to locate the property on the raster map. Theuser can visually verify the location of the property as marked on thedisplayed raster map, and can at that point examine the flood zoneindications on the raster map. The system can also generate, store, andproduce flood zone certificates according to the flood zonedetermination.

[0082] The georeferencing of the non-georeferenced FEMS maps isdescribed in the '849 application A digital map image is consideredgeoreferenced if a pair of mathematical functions, f, and g, have beendefined that can be used to convert back and forth between thecoordinates of the map image (as defined by the pixels of the image) andthe corresponding longitude and latitude of the location of that point.

[0083] That is, f and g do the following:

[0084] 1. If (x,y) represents a location on the digital map image, thenf(x, y)=(Lon, Lat) represents the longitude and latitude of thecorresponding physical location.

[0085] 2. If (Lon, Lat) represents a physical location that lies withinthe region covered by the map, then g(Lon, Lat)=(x, y) represents thepoint on the digital map image that corresponds to that longitude andlatitude.

[0086] Here, x and y represent the natural internal coordinate system ofthe map image. Typically, as described above, a digital raster map imageuses the pixels of its image as a natural coordinate matrix. However, inmost cases, a vector—based map image uses longitude and latitude as itsinternal coordinate system; if so, it can be considered to be triviallygeoreferenced already. Therefore the functions f ( ) and g ( ) above arenon-trivial georeferencing functions required to convert back and forthbetween coordinate systems.

[0087] Once the raster map images of the preferred embodiment aregeoreferenced, the system can easily locate specific geographiclocations thereon. This is important, because, as discussed above, eachrectangle of the virtual grid ultimately has associated therewith a listof all map insets that intersect it. Thus, when a specific geocodedlocation is entered, the grid rectangle containing the address isimmediately locatable. If a single inset is on the rectangle's list, itis that very inset and its panel map that exclusively contain the soughtafter flood zone information. If, on the other hand, the list containstwo or more insets, the procedures described earlier lead to adetermination of which is the only appropriate inset and associatedpanel map by which to evaluate the location. FIG. 8 is a process chartshowing the steps involved in the method of the present invention, asset forth immediately above and earlier in this description.

[0088] While the process of the preferred embodiment has assumed thatthe required paper map has been previously georeferenced, it is alsopossible that the property in question is only found on a traditionalpaper map. If this is the case, the user may scan the paper map into thedata processing system to create a raster map image. The image may thenbe georeferenced to provide georeferencing functions for convertingbetween the raster map image coordinates and the geographic coordinates.Once this has been done, the process of the preferred embodiment can beperformed as described above.

[0089] It is important to note that while the present invention has beendescribed in the context of a fully functional data processing systemand/or network, those skilled in the art will appreciate that themechanism of the present invention is capable of being distributed inthe form of a computer usable medium of instructions in a variety offorms, and that the present invention applies equally, regardless of theparticular type of signal bearing medium used to actually carry out thedistribution. Examples of computer usable mediums include: nonvolatile,hard-coded type mediums such as read only memories (ROMs) or erasable,electrically programmable read only memories (EEPROMs), recordable typemediums such as floppy disks, hard disk drives and CD-ROMs, andtransmission type mediums such as digital and analog communicationlinks.

[0090] While the invention has been particularly shown and describedwith reference to a preferred embodiment, it will be understood by thoseskilled in the art that various changes in form and detail may be madetherein without departing from the spirit and scope of the invention.

What is claimed is:
 1. A computer-implemented method of evaluating acharacteristic or trait prtesent at and in the vicinity of a geographiclocation from plural, initially non-georeferenced maps that depict thecharacteristic or trait being evaluated and other related data and thathave been georeferenced, which comprises: (a) constructing a virtualbounding box around each inset of the maps; (b) defining a virtualrectangular geographic grid system covering the total area covered bythe maps; (c) for each grid rectangle that intersects an inset boundingbox, tracing the inset enclosed by the bounding box to determine ifthere is intersection of the grid rectangle and the inset; (d) if thereis intersection of a grid rectangle and an inset, adding the identity ofthe inset to a list associated with the grid rectangle; (e) geocodingthe location of the geographic location; and (f) examining the insetscontained in the list associated with the one grid rectangle containingthe geocoded location, and, using the data thereon, performing theevaluation.
 2. A method as in claim 1, wherein: step (f) includesexamining insets contained in the lists associated with grid rectanglesthat do not contain the geocoded location but abut and are proximate theone grid rectangle containing the geocoded location.
 3. A method as inclaim 1, wherein: the data for performing the evaluation is properlyobtainable only from one of the maps, which method further comprises:(f₁) examining the list of insets contained on the list associated withthe grid rectangle containing the geocoded location; and (i) if there isonly one inset on the list, using the data on its map to complete theevaluation, or (ii) if there is more than one inset on the list,inspecting their respective insets to determine which inset-containingmap is appropriate and using the data on that one map to complete theevaluation.
 4. A method as in claim 3, wherein: the characteristic ortrait is a geographic, demographic, ecological or climatological trait.5. A computer-implemented method of performing trait evaluations forreal property using plural, initially non-georeferenced flood maps,comprising: (a) forming a raster image of each flood map; (b)constructing polygons enclosing each inset of the flood maps; (c)georeferencing the flood maps by the use of another georeferenced mapthat depicts the same geographic area as the flood maps; (d)constructing a bounding box around each inset polygon; (e) defining avirtual rectangular geographic grid system; (f) for each grid rectanglethat intersects an inset bounding box, tracing the inset enclosed by thebounding box to determine if there is intersection of the grid rectangleand the inset; (g) if there is intersection of a grid rectangle and aninset, adding the identity of the inset to a list associated with thegrid rectangle; (h) geocoding the location of the geographic location;and (i) examining the insets contained in the list associated with theone grid rectangle containing the geocoded location, and, using the datathereon, performing the evaluation.
 6. A method as in claim 5, wherein:the flood maps are FEMA paper maps.
 7. A method as in claim 5, wherein:the characteristic or trait is a geographic, demographic, ecological orclimatological trait.
 8. A computer system for evaluating acharacteristic of a geographic location from plural, initiallynon-georeferenced maps that depict the characteristic being evaluatedand other related data, the maps having been georeferenced, whichcomprises: (a) first facilities including a pointing device forconstructing a virtual bounding box around each inset of the maps; (b)second facilities for determining each grid rectangle that intersects abounding box and for tracing the inset enclosed by the bounding box todetermine if there is intersection of the grid rectangle and the inset;(d) third facilities for determining whether there is intersection of agrid rectangle and an inset, and, if there is, for adding the identityof the inset to a list associated with the grid rectangle; (e) fourthfacilities for geocoding the location of the geographic area; and (f)fifth facilities for examining the list of insets contained on the listassociated with the grid rectangles containing the geocoded location andthose grid rectangles proximate there, and, using the data thereon, forperforming the evaluation.
 9. A system as in claim 8, wherein: thecharacteristic or trait is a geographic, demographic, ecological orclimatological trait.
 10. A system as in claim 8, wherein: the data forperforming the evaluation is properly obtainable from only one of themaps, and wherein: (f₁) the sixth facilities perform so that if there isonly one inset on the list, the data on its map is used to complete theevaluation, or, if there is more than one inset on the list, theirrespective insets are inspected to determine which inset-containing mapis appropriate and the data on that one map is used to complete theevaluation.
 11. A system as in claim 10, wherein: the map is a rastermap based on x,y coordinates, the georeferencing of the map beingachieved by calculating a georeferencing functionf(x,y)=(latitude,longitude) and a georeferencing functiong(lat,lon)=(x,y), the georeferencing functions being stored by thecomputer system.
 12. A computer system for performing flood zonecertifications for real property using plural, initiallynon-georeferenced flood maps, comprising: (a) a scanner for forming araster image of each flood map; (b) a pointing device for constructingpolygons enclosing each inset of the flood maps; (c) first facilitiesfor georeferencing the flood maps by the use of a georeferened map thatdepicts the same geographic area as the flood maps; (d) a pointingdevice for constructing a bounding box around each polygon; (e) secondfacilities virtually overlying the vector map with a virtual grid systemdefined by grid rectangles; (f) third facilities for determining eachgrid rectangle that intersects a bounding box of an inset, and, if itdoes, for tracing the inset polygon enclosed by the bounding box todetermine if there is intersection of the grid rectangle and the insetpolygon; (g) fourth facilities for determining whether there isintersection of a grid rectangle and an inset polygon, and, if there is,for adding the identity of the inset polygon to a list associated withthe grid rectangle; (h) fifth facilities for geocoding the address ofthe property; and (j) sixth facilities for examining the list of insetpolygons contained on the list associated with the grid rectanglecontaining the geocoded address; and (k1) if there is only one polygonon the list, for using the data on its flood map to complete the floodzone certification, or (k2) if there is more than one polygon on thelist, for inspecting the polygons to determine which polygon-containingflood map is appropriate and for using the data on that one flood map tocomplete the flood zone certification.
 13. A System as in claim 12,wherein: the flood maps are FEMA paper maps.
 14. A system as in claim13, wherein: the raster map images of the FEMA flood maps are based onx,y coordinates, the georeferencing of the flood maps being achieved bycalculating a georeferencing function f(x,y)=(latitude,longitude) and ageoreferencing function g(lat,lon)=(x,y), the georeferencing functionsbeing stored by the computer system.
 15. A computer-implemented methodof preparing plural, initially non-georeferenced maps that depict acharacteristic or trait at and near a geographic location so as to beusable for evaluating the characteristic or trait at the location, themaps having been georeferenced, which method comprises: (a) constructinga virtual bounding box around each inset of the maps; (b) defining avirtual grid of identical rectangles corresponding to the total areacovered by the maps; (b) for each grid rectangle that intersects abounding box, tracing the inset enclosed by the bounding box todetermine if there is intersection of the grid rectangle and the inset;and (d) if there is intersection of a grid rectangle and an inset,adding the identity of the inset to a list associated with the gridrectangle, so that thereafter, when the location is geocoded and thelist of insets associated with the grid rectangle containing thegeocoded location is examined, data on such insets permits theevaluation to be effected.
 16. An item of commerce, comprising: acomputer-usable, portable memory unit containing the data of step (d) ofclaim
 15. 17. An item of commerce, comprising: a data transmissionmedium carrying the data of step (d) of claim
 15. 18. An item ofcommerce, comprising: a memory unit containing computer instructions foreffecting the method of claim
 1. 19. An item of commerce, comprising: amemory unit containing computer instructions for effecting the method ofclaim
 5. 20. An item of commerce, comprising: a data transmissionconnected to a general purpose computer for instructing the computer toeffect the method of claim
 1. 21. An item of commerce, comprising: adata transmission connected to a general purpose computer forinstructing the computer to effect the method of claim 5.